In mobile telecommunication networks, when User Equipment (UE) is connected to the network (RRC_CONNECTED state) it can be configured to receive and/or transmit data in discontinuous time periods, the duration and frequency of which are controlled by the base station (eNodeB). This discontinuous reception/transmission is called DRX/DTX and allows the UE to turn off its transceiver circuitry during the periods when it is not supposed to receive and/or transmit data from the base station, thereby reducing power consumption. Additionally, during periods that the UE is not scheduled to receive data, it is also required to perform some signal strength measurements to assist the network in making inter frequency handovers (for example between cells operating at different frequencies) or inter network (RAT) handovers (for example from UMTS to GSM). There is therefore a requirement to configure the UE with a DRX/DTX schedule or pattern so that the UE has maximum power saving and sufficient gaps made available for the UE to make the above measurements.
During RAN2#58, some agreements were made on DRX handling for non real time (NRT) services, such as web browsing, FTP etc. The NRT DRX handling that was agreed involves the provision of periodic fixed duration reception windows in which the UE can receive data from the base station. During the on duration, the UE is intended to monitor the L1/L2 control channel for possible resource allocations. During the off duration, the UE is not required to monitor the L1/L2 control channel, it can turn off its receiver circuit, and can perform inter-frequency/inter RAT measurements, if needed. However, the agreements do not consider the handling of real time (RT) services such as VoIP and mixed traffic (NRT and RT) scenarios.